Fluid hoist



J. P. kiElL FLUID HOIST Filed Nov. 1

1920 2 Sheets-Sheet 2 Patented Nov. Ed, 1923.

Waste JULIUS 1P. HEIL, OF MILWAUKEE, WISCONSIN.

FLUID HOIST.

Application filed November 1, 1920'. Serial No. 421,175.

T 0 all whom it may 0012 oer-n:

Be it known that I, JULIUS P. HEIL, a citizen of the United States, and resident of Milwaukee, in the county of'Milwaukee and State of lVisconsin, have invented new and useful Improvements in Fluid Hoists, of which the following is a description, reference being had to the accompanying drawings, which are a part of this specification.

This invention relates to improvements lIl fluid hoists.

It is one of the objects of the present invention to provide a fluid hoist more particularly, although not solely adapted for operating the dump bodies of power driven trucks.

A further object of the invention is to provide a fluid hoist which may be easily used in connection with any standard make of truck and dump body, and which will not require any space between the forward end of the body and the cab or seat of the truck.

A further object of the invention is to provide a fluid hoist which Will permit the positioning of the body with relation to the front and rear axles to more evenly distribute the load thereon and thereby in crease the capacity of the truck.

A further object of the invention is to provide a fluid hoist in which the use of outside pipes or ducts is eliminated.

A further object of the invention is to provide a fluid hoist which is -'a unitary structure and is self contained and has therefore a minimum number of arts and may be easily mounted on a truck.

further object of the invention is to provide a fluid hoist which Will automatically stop the further tilting of the'truck body when said body reaches its predetermined dumping inclination.

A further object of the invention is to provide a fluid hoist in which the piston controls its own movement without stopping the operation of the pump and will automatically stop when the dump body of the truck reaches its predetermined unloading angle even though the pump continues to operate.

A further object of the invention is to provide a fluid hoist in which the dump body of the truck may be maintained in its upper position for an indefinite period while the pump and connected parts continue to operate without injury to the hoist.

A further object of the invention is to provide a fluid hoist in which a single cylinder and piston are used for ti'ltingthe dump body.

A further object of the invention is to provide a fluid 'hoist in which the piston itself serves to automatically stop the supply of the fluid medium to the pump when the said piston reaches sition of rest.

A further object of the invention is to provide a fluid hoist which is of simple construction, is strong and durable and is well adapted for the purpose described.

With the above and other objects in view, the invention consists of the improved fluid hoist and its parts and combinations as set forth in the claims, and all equivalents thereof.

In the accompanying drawings in which the same reference characters indicate the same parts in all of the views:

F ig. 1 is a side view of the rearJportion of a motor truck provided with the im proved fluid hoist, parts being broken away and the body portion being shown in tilted position by dotted lines;

Fig. 2 is a transverse sectional view, on a larger scale, taken on line 22 of Fig. '1; an

Fig. 3 is a vertical sectional view taken on line 3-3 of Fig. 2.

Referring to the drawings, the numeral 5 indicates a portion of a motor truck, 6 the side members of 'the frame or chassis, 7 the cab. or seat portion and 8 the tiltable load carrying body of the truck. Said body near its rear end portion is pivotally connected to the opposite outer side members 6 by a pivot and bracket means 9.

The improved fluid hoist comprises a cylinder 10 having at its upper opposite sides outwardly projecting portions 11 having alined trunnion recesses 11' for pivotally receiving the inwardly projecting trunnions 12 of the brackets 13 which rest on and are bolted to the outer side members 6 of the chassis. The cylinder is pivotally supported on said trunnions and depends downwardly therefrom and is provided with a piston 14 reciprocally positioned therein. The piston is mounted on the lower end portion of a rod or tube 15 which extends upwardly through the upper closed end of the cylinderand is provided with an upper eyed end 16. Said upper eyed end is pivotall connected to the truck body beneath the ottom por a predetermined polit) lid

tion by a pivot rod 17 which extends transversely of said bottom portion and into bearin members 18 mounted on longitudinal reinforcing channel -members 19 thereof. The pivotal connections of the cylinder-and the piston rod permit the. rod and cylinder to tilt and aline with said pivotal connections while the truck body is traveling throu h its arc of movement to an inclined unloa in position.

The cy inder is formed with lower ports 20 and 21 and upper ports 22 and 23 through which the fluid medium flows in passing from one side of the piston to the other. The port'20 is in communication with dust 24 which is formed in the front wall of the cylinder and leads upwardly from said port 20 to a pressure duct25 and the said duct 25 and the port 22 extend outwardly and into a gear pump 26 mounted on the upper front portion of the cylinder 10, and serve respectivelyas the inlet and outlet openings to said pump. The duct 25 is provided with a ball check valve 25' which opens downwardly to stop the movement of the fluid medium in the opposite .direction. Une of the gears 27 of the pump26 is con nected to the transmission gearing motor vehicle by a shaft 29 and the 'two pump gears are rotated thereby. The rotation of said shaft 29 is controlled by a lever 30 positioned within cab 7. The opposite side portion of the cylinder 10 is also provided with a duct 31 which leads upwardly from the discharge port 21 and connects with a manually controlled valve 32 which is mounted transversely on the rear up er portion of the cylinder. The ort 23 a so connects with the valve 32 an when said valve is in open position the fluid medium can pass upwardly throu h the duct 31, the valve 32, the duct 23 an into the cylinder above'the piston to permit the piston to descend. and lower the dump body. As the valve 32 may be opened to a greater or less extent, the speed of the downward movement of the piston may easil be controlled by turning the valve to t e desired extent.

Said valve is controlled from the cab by a lever 33 having a rod connection 34 with the valve arm 35.

The upper ports 22 and 23 are diametrically opposite each other and are positioned a short distance below the upper end or head of the cylinder, the port 23 being closer to the head than the port 22 so that when said piston is in itsu per position it will close the port 22 and part y close the port 23 and automatically stop the supply of fluid medium to the pump and further movement of the piston upwardly, even though the pump gears continue to rotate as they will merely churn the fluid medium and cannot force any more into the cylinder beneath the piston.

28 of the" As considerable space within the cylinder is required to accommodate the piston rod or tube when in its inner position, less fluid medium is used when the piston is in its inner position than when in its outer position and to supply the varying amounts a tank 36 is mounted on the upper end or head portion of the cylinder and is in communication with the upper end portion of the cylinder by an opening or port 37. The surplus fluid medium is forced upwardly into the tank by the downward movement of the piston rod and flows by gravity from the tank to the cylinder when the piston rod is moved upwardly.

In use the fluid hoist is mounted on a motor truck in the manner shown in Fig. l, and when it is desired to dump the contents of the truck body the transmission controlling lever is operated to transmit motion from the transmission to the pump and the operation of the ump will draw the fluid medium from a ve the piston and force it into the cylinder below the piston and force said piston upwardly.

he upward movement of the piston will tilt the truck body and unload the contents thereof. When the piston reaches its-uppermost position it will close the port 22 and partly close the port 23 and thus automatically shut 0d the su ply of fluid medium or oil to the pump. The pump may continue to operate but as its supply of oil is cut ofi, it cannot ump any more oil into the cylinder beneat the piston and the upward movement of the piston will automatically stop. This feature is very desirable as it eliminates any dan r or damage to the hoist in the event t at the operator inadvertently ne lects to stop the operation of the pump. The piston will remain in its upper position whether or not the pump is in operation. ll it is now desired to lower the truck body the valve rod 34 is operated to open the valve 32 and. when opened, the oil in the c linder helow the piston can flow upwardly through the duct 31 and the valve and through the partly opened upper port 23 back into the cylinder above the piston and thus permit the valve controlled descent of the piston and the truck body. The port 23 is always sufliciently open to permit the initial flow of the oil to enter the cylinder above the iston when the valve is in open position. he s eed of lowering the truck ody is control ed by openin or closing more or less the port of the va ve.

lit is to be understood that one or any number of cylinders may be used without departing from the spirit and scope of the invention. 1

From the foregoing description it will he seen that the fluid hoist is of very simple construction and may he easil mounted on a motor truck having a tiltah e body.

till

lit

inder having a pair of ports at opposite end ram-sea What ll claim as my invention is: l. A fluid hoist, comprising a single cylportions, a piston within .the cylinder and between the pairs of ports and having a stem extending through one end of the cylinder,

ducts on the opposite sides of the cylinder for connecting the ports of the opposite ends together in pairs, means on one side of the cylinder intersecting one of the ducts for moving a fluid medium from one side of the piston to the other to move the piston in one direction to a predetermined position of rest, said position of rest closing one of the ports and automatically stopping the move-' ment of the fluid medium to the moving means without stopping the operation of the moving means, and means on the other side of the cylinderintersecting the other duct for controlling the movement of the fluid medium through the other ports and the movement of the piston to its other position of rest.

2. A fluid hoist, comprising a cylinder having a air of ports at opposite ends, a piston wit in the cylinder and between the pairs of ports and havinga stem extending through one end of the cy inder, ducts on the opposite sides of the cyllnde'r for connecting the ports of the opposite ends together in pairs, a pump positioned on one side of the cylinder and intersecting one of the ducts for moving a fluid medium from one side of the piston to the other'to move the piston in one direction to a predetermined position of rest, said position of rest closing one of the ports and automatically stopping the movement of the fluid medium to the pump without stopping the operation of the pump,

Oil

and a valve ositioned on the opposite side of the cylin er and intersecting the other duct for controlling the movement of the fluid medium through the otherports and the movement of the piston to its other position of rest.

3. A fluid hoist, comprising a cylinder having pairs of ports adjacent its upper and lower ends, a piston within the cylinder and between the pairs of ports and having a stem extending through the upper end of the c linder, ducts on opposite sides of the cylin er for connecting the upper and lower ports together in pairs, a pump positioned on one side of the cylinder and intersecting one of theducts, and a valve on the other side of the cylinder intersecting the other duct, said piston in its upper position of rest closing the upper port of the duct intersected by the pum 4. A fluid hoist, comprising a cylinder having pairs of ports adjacent its upper and tersecting one of the ducts, and a valve on the other side of the cylinder intersecting the other duct, said piston'in its upper position ofrest' closing the upper port of the duct intersected by the pump and partly closin the other upper port.

5. fluid hoist, comprising a cylinder having pairs of ports at its upper and lower ends, one of said upper orts being in a higher horizontal plane than the other, a piston Within the cylinder and between the pairs of ports and having-a stem extending upwardly through the upper end of the cylinder, ducts on opposite sides of the cylinder for connecting the upper and lower ports together in pairs, a rotary gear pump on one side of the cylinder intersecting one of the ducts, and a valve on the other side of the cylinder intersecting the other duct, said piston when in its upper position of rest closing the lower of the two upper ports to automatically stop the flow of the fluid. medium therethrough and the upward movement of said piston.

6. A fluid hoist, comprising a cylinder having two ports in its upper end and two ports in its lower end, said cylinder also having two ducts positioned on opposite sides of the cylinder which connect one of the up per and one of the lower ducts together in pairs, one of said upper ports being in a higher horizontal plane than the other, a piston within the cylinder and having a stem extending through the upper end of the cylinder, a rotary gear pump on one side of the cylinder intersecting the duct extending to the lower of the upper ports for drawing a fluid medium from the cylinder above the piston and forcing it back into the cylinder beneath the piston, a check valve within the duct between the pump and the lower port in the cylinder connected to said duct, and a valve on the other side of the cylinder for intersecting the other duct to permit the fluid medium to flow from the cylinder beneath the piston to the cylinder above the piston, said piston when in its upper position of rest closing the lower of the two upper ports to automatically'stop the upward movement of the piston.

7. A fluid hoist, comprising a support, a cylinder fulcrumed thereon and having pairs of ports formed in its upper and lower end portions, a piston within the cylinder and between the ports and having a stem extending through the upper portion of the cylin der, a tiltable body positioned above the cylinder and pivotally connected to the upper end portion of the piston stem, ducts positioned on opposite sides of the cylinder for connecting the upper and lower ports together in pairs, one of the upper ports being in a higher horizontal plane than the other, a power driven gear pump on one side of the cylinder intersecting the duct connected to the lower of the upper ports for drawing afluid medium from the cylinder above the piston and forcing it back into the cylinder beneath the piston, a check valve within the duct and between the pump and the lower port in the cylinder connected to said duct, :1 manuall operable valve on the other side of the cy inder for intersecting the other duct to permit the fluid medium to flow from the cylinder beneath the piston to the cylinder above the piston, and a tank for receiving the medium from the cylinder, said piston when in its upper position of rest closing the lower of the two upper ports to automatically stop the upward movement of the piston.

In testimony whereof, I aflix my signature. v

JULIUS P. HEIL; 

